By ÁLVARO SERRANO

The 33-year-old Swiss is the most successful player to compete at the Barclays ATP World Tour Finals, compiling a 44-11 record and claiming a record six titles in 2003-04, 2006-07 and 2010-11. He breaks the record of consecutive years qualifying for the championship, a mark he previously shared with Ivan Lendl (1980-91).